In the adult, there is potentiation of ACTH release with CRH challenge in the setting of severe illness. In our results, the ACTH test demonstrates that peak cortisol release is decreased in premature infants that have been ill during the first week of life, is greater in the 4 day old than the six day old infant. These results suggest that, unlike the adult where the HPA is activated during a state of illness, the ill premature infants may not respond in this fashion and may be at-risk of low release cortisol.